For the code to work, you need to have the app called Arduino Bluetooth Control and you will need to have the BluetoothSerial.h library.

#include <BluetoothSerial.h>

BluetoothSerial SerialBT;

// Your pin assignments

#define RED_PIN   12

#define GREEN_PIN 14

#define BLUE_PIN  27

void setup() {

  Serial.begin(115200);

  SerialBT.begin(“ESP32_LED”);

  ledcAttachPin(RED_PIN,   0);

  ledcAttachPin(GREEN_PIN, 1);

  ledcAttachPin(BLUE_PIN,  2);

  ledcSetup(0, 5000, 8);

  ledcSetup(1, 5000, 8);

  ledcSetup(2, 5000, 8);

}

void loop() {

  if (SerialBT.available()) {

    String data = SerialBT.readStringUntil(‘\n’);

    if (data.length() == 9) {

      int r = data.substring(0, 3).toInt();

      int g = data.substring(3, 6).toInt();

      int b = data.substring(6, 9).toInt();

      // Direct, unmodified output

      ledcWrite(0, r);

      ledcWrite(1, g);

      ledcWrite(2, b);

      Serial.printf(“RGB set to: %d, %d, %d\n”, r, g, b);

    }

  }

}